<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
        <asp:Panel ID="Panel1" runat="server" Height="50px" Width="125px">    
        </asp:Panel>
        <asp:HiddenField ID="HiddenField1" runat="server" />
        <asp:Button ID="Button2" runat="server" Text="Button" OnClick="Button2_Click" OnClientClick="saveValue();" />
<script>
function saveValue()
{
    var obj=document.getElementById("Panel1").getElementsByTagName("input");
    for(var i=0;i<obj.length;i++)
   {
       if(obj.type="text")
                document.getElementById("HiddenField1").value+=obj[i].value+",";
   }  
   alert(document.getElementById("HiddenField1").value)
}
</script>

------解决方案--------------------
我们只能跟随问答机器人后面接点分
SF都让他一个人占领了 速度太快

------解决方案--------------------

我也来凑个热闹,企图获得重金!!
生成一个TextBox,多个依次类推,放一个Hidden1,中间变量

页面html
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />
<asp:Button ID="Button2" runat="server" onclick="Button2_Click" Text="Button"  OnClientClick="test()" />
<asp:Panel ID="Panel1" runat="server">
</asp:Panel>
<input id="Hidden1" type="hidden"  runat="server" />

js:
<script type="text/javascript">
   function test() {
      document.getElementById("Hidden1").value = document.getElementById("myT1").value;
      }
</script>

c#
   protected void Button1_Click(object sender, EventArgs e)
   {
       this.sText();//动态生成TextBox
   }
   protected void Button2_Click(object sender, EventArgs e)
   {
       ViewState["t1"] = Hidden1.Value.ToString();//获得中间变量
       this.sText();//动态生成TextBox
       ((TextBox)Panel1.FindControl("myT1")).Text = ViewState["t1"].ToString();//赋值
   }

   private void sText()
   {
       TextBox myT1 = new TextBox();
       myT1.ID = "myT1";
       Panel1.Controls.Add(myT1);
   }

------解决方案--------------------
探讨

protected void btn1_Click(object sender, EventArgs e)